The conventional wire feeding and measuring apparatus feeds a wire from a supply reel in an axial direction to wire processing equipment. The processing equipment may, for example, be a wire cutter or a cutter-stripper which serves the wire into segments of predetermined length and strips the insulation from the severed end of the wire.
In a typical wire feeding and measuring apparatus, as described in U.S. patent application Ser. No. 07/480,770, filed Feb. 15, 1990, the wire is fed by a pair of cooperating endless feed belts formed of an elastomeric material which engage opposite sides of the wire. The feed belts are intermittently driven by a servo motor which is programmed to operate the feed belts forwardly to feed a predetermined length of wire and then stop movement of the wire. A wire measuring means in the form of a measuring wheel, that is located upstream of the feed belt, measures the actual distance the wire has moved and provides a feedback signal through an encoder to a controller. In the event wire slippage occurred during forward feeding movement, the controller employs the feedback signal to ascertain whether less or more wire than the predetermined length has actually been fed, and commands the feed belts to feed the wire either forwardly or in reverse to correct for the discrepancy. The wire measuring wheel senses the direction and distance the wire moves during the correction operation and signals the controller accordingly, thereby enabling the controller to actuate the feed means to stop wire movement when the predetermined length has been fed.
The typical wire feeding and measuring machine, operating in the manner described above, is very accurate and repeatable, if a single gauge of wire is processed. However, if a different gauge of wire, or a different type or thickness of insulation is employed, the system must be recalibrated. Recalibration for a different gauge or type of wire requires the initial length of wire to be measured to determine whether the length has been precisely cut to the predetermined length and to reset the machine, if there is a variance. After resetting, the procedure is repeated to check the actual cut length against the predetermined length. This trial and error calibration procedure not only is time consuming, but also can result in considerable scrappage of wire.